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Power calculator

Power is the rate of doing work. Find power, work or time from the other two.

How it works Report a problem

Power Calculator

P = W / t · Work · Time

P = W / t  |  Power in Watts (W)

About the Power calculator

Power is the rate of doing work. Find power, work or time from the other two.

How to use the Power calculator

  1. Choose what to solve for: P — Power (W), W — Work (J) or t — Time (s).
  2. Enter the known values and press Calculate.

Formula and method

P = W ÷ t, so W = P × t and t = W ÷ P. One watt is one joule per second.

Worked example

Doing 5,000 J of work in 10 seconds requires 500 W.

Tips

  • 1 horsepower is about 746 watts.
  • A kilowatt-hour is 3.6 million joules.

Frequently asked questions

What is the difference between energy and power?
Energy is the total amount. Power is how quickly it is used.